There are numerous occasions in the diagnostic, prophylactic and treatment practice of medicine wherein an agent, medicant, or medium is preferably delivered to a specific site within the body, as opposed to a more general, systemic introduction. One such exemplary occasion is the delivery of contrast media to coronary vasculature in the diagnosis (i.e., angiography) and treatment (i.e., balloon angioplasty and stenting) of coronary vascular disease.